I was sitting in my room and I looked out my windows which faces east and I could see that it was a perfectly clear day apart from two clouds. Both clouds were in the east and one was the apparent size of a thumb, the other half this size. I also noticed that the vapour trail of a jet was stretching from roughly the SE to NW and its leading end was obscured by the smaller cloud. It is always my natural reaction to watch, for a few seconds, the passing of a jet as it goes overhead but as yet this jet had not moved from behind the small cloud. It should have taken a second or less for a jet to travel the apparent width of this tiny cloud. After maybe ten seconds I was expecting to see burning pieces of jet fall from the sky as this was the only reason I could come up with as to why this jet had apparently stopped. Time went by, maybe 20-30 secs, I can't remember the time scale that well because I was just astounded that the jet seemed to have stopped. Then I saw what looked like a triangular object, an isoceles possibly moving in a smoothly curving path from a point which was many degrees above and to the right of this small cloud. It's apparent size was 2 or 3 times that of a jet, its surface was not smooth but appeared to have details which were beyond my vision. It had no vapour trail and it moved faster than a jet possibly twice the speed, it is hard to compare since it moved in a long arc. At this point I was aware that something extremely mad was happening and that something weird was going to happen. This object, which seemed to appear from nowhere was swooping its way towards this little cloud where a jet was apparently stuck. Incidentally the jet was still 'stuck' while this thing was making its way. Obviously my heart was beating fast and my jaw was hanging and various expletives were repeating themselves in my head. Anyway, as soon as the object disappeared behind this cloud, the plane popped out! The object was gone and the jet continued on the same course indicated by it's pre! vious va pour trail i.e. SE to NW. I am an amateur astronomer and I where glasses with weak lenses. I have also seen other anomalous things when doing astronomy such as fast moving orange lights, which have also been reported by two others in the letters section of a UK astronomy magazine. You just can't make this story up. I am not seeking attention. Just read this and know that it actually happened. I will leave explanations to others.